c# 对加密的MP4文件进行解密

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

using System.IO;

namespace WindowsFormsApplication9

{

public partial class Form1 : Form

{

private string res = "";

public Form1()

{

InitializeComponent();

}

private void button1_Click(object sender, EventArgs e)

{

OpenFileDialog ss = new OpenFileDialog();

if (ss.ShowDialog() == DialogResult.OK)

{

res = ss.FileName;

}

fun();

}

public void fun()

{

FileInfo fileinfo = new FileInfo(res);

long len =160;

MessageBox.Show(len.ToString());

byte[] buff1 = new byte[len];

byte[] buff2 = new byte[160];

FileStream fs = new FileStream(res, FileMode.Open);

fs.Read(buff1, 0, (int)len);

fs.Close();

OppositeByteArray(buff1,ref buff2);

FileStream fw = new FileStream(res, FileMode.Open);

for (int i = 0; i < 160; i++)

{

fw.WriteByte(buff2[i]);

}

//fw.Write(buff1, 0, (int)len);

fw.Write(buff1,0,(int)len);

fw.Close();

fileinfo = new FileInfo(res);

}

/// <summary>

/// 把一个字节数组按位取反，得到一个新的字节数组

/// </summary>

/// <param name="inputData"></param>

/// <param name="outputData"></param>

public static void OppositeByteArray(byte[] inputData, ref byte[] outputData)

{

int len = inputData.Length;

int temp;

for (int i = 0; i < len; i++)

{

temp = (int)inputData[i];//原字节数组字节转成int型

outputData[i] = (byte)~temp;//取反后赋给输出字节数组

}

}

}

}